The invention relates generally to mechanical linkages by which a working element may be driven by a power source. More particularly, the invention provides a user-adjustable linkage for use in a electric motor-driven carpet stripper used to strip carpet and similar floor coverings from a floor.
Motor-driven carpet strippers of the general type in which the invention may find use are known in the art. FIG. 1 is a perspective view of this kind of carpet stripper. The carpet stripper 5 is built around a frame 7 with a working element in the form of an angled blade 10 at one end of the frame, and a pair of wheels 13 at the other. Handles 15 mounted on a shaft 17 attached to the wheel end of the frame allows an operator to steer the stripper, and an electrical motor 18 drives the blade through a linkage that will be described in more detail below. Power is supplied to the motor though a long electrical cord 20 connected to a switch 23 mounted near the handles. Finally, a weight 25 holds the blade down as it slides under a carpet 28 or a similar floor covering.
A variety of linkages have been used to connect the blade 10 to the driving motor 18. One such linkage is shown in FIG. 2, which depicts the underside of a representative prior art carpet stripper 5. This view shows the bottom of the stripper's frame 7. An eccentric cam 30 is fixed to the electric motor's driveshaft 33.
The eccentric cam drives a first end 35 of a driven member 32 in an orbital motion, thereby driving the blade 10 at the second end of the driven member. In this prior art embodiment, motion of the driven member is further constrained by a linkage arm 40, which is mounted to the frame and driven member at a pair of pivot points, frame pivot point 43 and driven member pivot point 45.
Motor-driven carpet strippers of the general type shown in FIGS. 1 and 2 have proved useful and have found considerable acceptance in the industry. It has been found, moreover, that different blade motions may be more useful for different floor coverings, such as different carpets, tile, vinyl floor coverings, etc., or that different blade motions may be preferable to different operators. A variety of linkages has been employed between the motor and the blade, each linkage being constructed to yield a somewhat different motion for the blade. These blade motions may be primarily (1) orbital, with the driven member and blade rotating about a more or less fixed pivot point; (2) reciprocal, with the blade being driven back and forth in a line parallel to the shaft of the handle; (3) transverse, with the primary motion of the blade being back and forth in a direction parallel to the axle between the wheels; or virtually any imaginable combination of the previous three motions.
Operators and flooring companies have thus been led to keep on hand a range of different strippers so that a desired one can be chosen as desired by a particular operator or as particularly appropriate for a given flooring. This is less than ideal, however, because it requires having more strippers on hand than would otherwise be required so that a desired one will be available for use. A need exists, therefore, for a means by which the motion of a particular stripper could be adjusted to suit the requirements of a given floor covering or to match the preferences of a particular operator. The present invention meets this need and provides other advantages that will be best appreciated by reference to the detailed description and figures that appear in this document.